Process and apparatus for fractional distillation and condensation.



v I. W. AYLSWORTH.

PRQCE SS AND APPARATUS FOR FRACTIONAL DISTILLATION AND CONDENSATIO N.

APPLICATION FILED NOV. 9, 1915- Patented Dec. 18, 1917. v

AITOH/VEY U 'E I 'r r i JONAS w. AYLswoR'rn, ornns'r ORANGE, unw JERSEY, ASSIGNOR 'zro comm usrrn comm or AMERICA, oF BLoom-FIELn, NEW JERSEY, A conronn'rrou ornnw JERSEY.

PROCESS AND APPARATUS FOR FRACTIONAL DISTI'LTIATION AND COINDENSATION.

Specification of Letters Patent. Patented Dec, 18, 191'? Application filed November 9, 1915. Serial No. 60,615.

To all whom it may concern:

Be it known that I, J oxss W. Answonm,

. a citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Processes and Apparatus for Fractional Distillation and Condensation, of which thefollowing is a. specification. I

My invention relates to a'process for the fractional separation of substances having slight differences in boiling points, andto a suitable apparatus for practising such process. Ordinarily,-substances of low boiling point, such as benzol, require a different apparatus, for fractional separation,.

which in my preferred apparatus, may beconsidered as 60 C. and 300 C.

The process .may be described briefly as consisting in evaporating the liquid to be fractionated in a suitable still and passing.

the distillate over. a condensing surface of large capacity relatively to the evaporating surface of the still. The temperature of the condensing surface is carefully regulated, so that it is equal to or slightly less than the boiling point of the fraction first tovbe obtained. Liquids which condense on.the condensing surface are continuously returned to the still and the vaporfwhich does not condense, namely, the fraction to be separated, is, passed into a cooled condensing coil and collected. The temperature ofthe large capacity condensing surface is then point which is to be separated, and the op eration repeated until the various desired fractions have been separated.

increased -to or slightly below the boiling point of the fraction of next higher boiling The process described may be practised by the. use of a horizontally disposed condensingcoil mounted in a closedreceptacle and connected respectively tothe still and awater-cooled condensing coil for receiving the desired fraction. The horizontal coil may be heated to the desired regulated temperature by rapidly circulating oil or other heating medium through the closed recep-' tacle andabout the convolutions of a horizontal coll therein, this circulating oil being heated, or, if necessary, cooled by a 7 heating or cooling device included in the circulating system, the heat added or ab stracted being carefully regulated, preferably by automatic thermostatic means. The lower loops of the convolutions of the horizontal coil are connected by return pipes to thestill. so that fractions condensed in the coil will be returned to the still, these return pipes being provided with gage glasses, so that operation of the system may be properly observed. q

It will be observed that the method requires the use of a condensing surface or coil hav.

ing relatively large capacity, namely, greater than-ten times that of the evaporating surface -of the still, in order that substances having boiling points close together may be I separated, The method also requires'that the heating fluid shall be circulated rapidly to keep it at uniform temperature throughout, and that regulated means-be employed for adjusting the temperature of the heating fluid, this heat being independent of that produced in the still. "With the'apparatus and process briefly described, substances having only one-half degreecentigrade dif ference in boiling point may be effectively separated in the case of high boiling point substances, and substances having even less difference in boiling point maybe effectively separated when low boiling point fluids are being operatedupon. a

My invention may alsobe practised in a modified manner, by using steam as the heating fluid, in place of oil or the like." In

this case the pressure 'ofv the steam supplied must be such as to provide the required temperature, which can be varied as the operations change, and a suflicient flow of steam about the condensing coil must be maintained.

In order that a. clearer understanding of my invention may be had, attention is here- I by directed tothe accompanying drawing forming part of this a plication and illustrating a preferred orm of apparatus whereby the described process may be prac.

through connection 6, heater 7 and pipe 8.

into receptacle 4, the oil returning to the pump by connection 9. Vapors which are not condensed in coil 3 pass by pipe 10, into the vertical condensing coil 11 contained in the water-cooled receptacle 12. The liquid condensed in coil 11 passes through. connection 13 or 13 to collecting vessel 14: or 14, connections 13 and 13 being provided with suitable valves 15 and 15'.. g The still 1 may be steam heated as is indicated, or heated by direct fire. When substances having boiling points up to approximately 220 C. are operated on,-the still is preferably heated by steam and in this case the operation is suitably carried on under a vacuum as this reduces the boiling point of the substance about 70 C. The vacuum may be provided on the system by providing vessels 14 and 14' with a T connection 16 which leads to a vacuum pump, the branches .of connections 16.being provided withsuitable valves 17 and 17.

W'th substances having very low boiling l oints, such as benzol, gasolene, etc., steam.

is used to heat the still, but theoperation is carried on under atmospheric pressure. When the system is used to operate upon substances whose boiling point is higher thanthat at which steam can supply the necessary heat, direct fire may be used under the still.

The receptacle 4 is provided with an expansion chamber 18 for the heating oil, which chamber may be provided with a cover 19 for introducing the oil .into the"'system. Chamber 18 should be of sufficient size to accommodate the oil when working athigh temperatures. Pipes 20 connect the bottom loops of coil 3 with a manifold 21, pipes 20 passing through suitable tight openings in thebottom of receptacle 4, and manifold 21 having a trap 22, which may be provided with a, still.

The return pipes 20 are provided with gage glasses 24 as it is'very necessary that the operation of the system should 'be observed. When the system is'in proper operation, condensed liquid will be observed.

dripping through ,all of the pipes 20, except the several last ones.

Bafile plates 25, 25 are preferably, positioned in receptacle 4: to extend alternately up from the bottom and down from the top in order to aid proper circulation of the pet-cpck 23, and leading into the,

- erate continuously and one vessel be supproper temperature of the fraction being' separated is attained. Means for determining the temperature of the heating fluid i within receptacle .4: is also provided. 'Whilethis may be a thermometer, it is preferably a thermostatic device '27, electr cal or otherwise, which may be connected, as is indi- 'cated at 28, to thethermostat regulator 29,

the function of which is to automatically.

completed through the solenoid and a battery 35 upon the closing of contacts in: the thermostat 27. This latter -may comprise a pair of conducting elements connected respectively to the wires 36, 36 of the solenoid circuit 28, which elements engage each other when a desired temperature" is attained by the bath in receptacle 4. When contact is thus made core 3t rises and causes valve 37 to partly close the passageway 38 of the valve casing 39, thus reducing the flowof gas through pipe 40 to the burner 32. Upon a slight reduction in the tem- 1 peratureof the l1eating fluid in receptacle 4 thereafter the contacts of thermostat 27 separate and-core 3-1t and valve 37 drop to open the gas passage more widely The contacts of thermostat 27 should be adjustable. so as to make contact at different de- 31. A pair of collecting vessels 14 and 14" are'provided, so that the system may opplied with a desired condensed fraction while the other is being emptied.

I am aware that it has previously been proposed to fractionally distil and condense certain substances, such as phenol, by passing the distillate over. acondensing surface,

having return pipes leading back to the ing points than that desired. Such systems are without flexibility or means for regulation. The novelty of, my improved still, for condensed fractions of higher boilprocess and apparatus chiefly" consists in the use of a condensing coil, preferably a continuous spiral, having the condensing surface greater than ten times that of the evaporating surface of the still; circulating the heating fluid rapidly to keep it-at uniform temperature throughout; the rovision of a heating means, independent the still, which can be regulated closely to determine quite exactly the temperature of-the sub. stances passing through the condensing coil;.

and the use of gage glasses in the return pipes leading from the coil back to the still.

The greater the condensing surface in the horizontal coil the more effective will be the apparatus in separating liquids having close boiling points.

As has been stated, my invention may also be practised by using steam as the heat- .ing fluid. In this case the pressure in the steam generator is carefully regulated, so that the temperature required for the first fractionating operation, corresponding to that pressure, will be obtained. In this case the heater 7 is rendered unnecessary, as well as the pump 5, steam entering receptacle 4 at one end, flowing therethrough, passing out at the other end, and escaping. When a" higher temperature is required for, subsequent' fractionating operations, the pressure in the steam line is correspondingly raised.

The steam must be passed through vessel 4' at a suflicient rate of flow. Substances having boiling points varying between say 100: C. and 150 C. may be operated upon by this method; if a vacuum is used in the distilling system, as stated above, substances having higher boiling points, under atmospheric pressure, are brought within the range above indicated. Thus the boiling points of the various cresolsmay be brought 7 to below 150 C; by the use of a-vacuum..

Having now described my invention, what I claim and desire to protect by Letter Patent is as follows a 1. In fractional distillation and condensation apparatus, adapted to operate on substances both of highand low boiling points,

the combination of a still, a closed receptacle, a condensing COll therein having its axis horizontal, and having a condensingsurface at least ten times as great as the evaporating surface of the still, a connection between said still and one end of the coil, means for condensing and collecting substances which do not condense in the coil, a connection between said means and the other end of the coil, means for obtaining the temperature in said last-named connection and in said receptacle, means for leading away condensed substances from the bottom loops of the coil, and a system for rapidly circulating a heating fillld. through said recept'a j cle, about said coil, comprising pipe connectlons, pumping means, and a heater regulable to heat the said heating fluid to any desired one of several temperatures in accordance with the indication of said temperature-obtaining means, substantially as. set forth.

2. In fractional distillation and condensation apparatus, adapted to operate on substances both of high and low boiling points, the combination of a still, a closed receptacle, a condensing coil therein, having its axis horizontal, and having a relatively large condensing surface in reference to the evaporating surface of the still, a water-cooled condensing coil, connections between said still and one end of said horizontal coil, and between the other end of said coil and said water-cooled coil, a system for rapidly circulating a heating fluid through said receptacle, about said horizontal coil, comprising pumping means of sufficient capacity to cause such rapid circulation, a heater for the fluid, andadjustable thermostatic means, governed by the tem- 

